Expert Advice: September/October 2007 Edition

Questions and answers from the Truck Trend Garage

BMW Dead BatteryQ: Two weeks ago, the battery in my 2002 X5 died while the BMW was parked in the garage overnight. I knew I hadn't left anything on, and the car was jumped and worked fine. The next day, it happened again--no radio, no lights, nothing.

This time it wouldn't even take a jump. I had it towed to an auto shop--even though I'd recently put in a new battery, the shop replaced it anyway and assured me they found nothing wrong with the electrical system. I went to pick it up, and it wouldn't start again. They retested the SUV and said it must've gotten run down from sitting in the sun (for a day?). I went to pick it up again, and it still wouldn't start. Now the shop is telling me they don't have a way to diagnose what's draining the battery. They just have to monitor it. In this day and age, is the only way to find out what's wrong by watching what kicks on? This auto shop isn't a BMW dealership but is authorized by BMW.

A: I'm not sure how something outside of the Bimmer service department is BMW authorized, but I'm confident a good battery won't go dead spending a day in the sun. It's got to be one of two things. Either they don't know how to correctly test for a parasitic amperage draw on the battery or it's an intermittent problem, which doesn't show up while testing. That the battery is out of commission every time you try to pick up the vehicle has me favoring curtain number one. A parasitic drain is current being used from the battery with the ignition off, doors closed, lights out, etc. This is necessary to keep your clock right and FM presets intact. It's considered normal when the amperage draw stays below a certain limit, in your case, 40 milliamps. Get it to a BMW service department before you pull your hair out. There have been notable parasitic draw problems from iPods and cell-phones, along with an onboard control unit failure that can be tough to diagnose.

Taking Off TaillightsQ:I need to remove the driver-side taillight from my Cadillac SRX (don't ask). I pulled away the interior plastic molding, but didn't see any screws to free the taillight. Can you help?

A:Keep digging. Presuming you removed the correct trim panel located behind the taillamp, there's still more work to do before you can get to the nuts that hold the assembly in place. On the right side, remove the rear speaker. Then undo the two nuts and remove the taillamp. On the left, remove the auxiliary blower motor fasteners and tilt the motor outward. It's worth noting that a small amount of condensation accumulating within a taillamp, or any other ventilated lamp assembly, is considered normal. If there's a fine mist or white fog in the corners that doesn't cover more than half the lens and appears only under humid conditions, don't replace the lamp assembly. The moisture should clear up in drier conditions or while driving with the lights on for an extended period of time. You may also compare both sides. If one has the same slight fog as the other, chances are it's normal. On the other hand, if you see water droplets covering more than half the lens, one lens is much wetter than the other, the water appears after rain or a car wash, a puddle accumulates in the bottom of the lens, or it doesn't eventually clear up with the lights on, then you have a real water leak that will require replacement of the assembly.

Good Vibrations GoneQ:My 2003 Toyota 4Runner V-8 Sport has two annoying traits that Toyota won't correct. First, when coming to a stop, completely stopped, or upon brake release, there's a pushing sensation like a clunk. Second, there's a slight vibration in the steering wheel, console, and armrests when the vehicle is under load at about 1200 to 2000 rpm. I also can feel it when the vehicle is stopped in Drive, foot on the brake, A/C on or off. Under acceleration there's an accompanying moaning or groaning sound. Although Lexus has issued several TSBs for the 4Runner's sister vehicle, the Lexus GX 470, Toyota insists these are "normal operating characteristics" of the 4Runner. My local Toyota dealer test drove, acknowledged, and documented the problems, but since there are no TSBs, can do nothing.

A:We'd hoped Toyota would've come out with something by now, but we couldn't find anything, either. Lexus TSB # DL001-04 refers to a driveline clunk in 2003-2004 GX 470s when coming to a stop, with a new propeller shaft (part #37110-6A480) used as a fix. While it sounds like the same condition on the same platform and drivetrain, there's nothing published that applies the repair to the 4Runner. And then there's Lexus TSB # ST004-04 dealing with a steering vibration and/or front driveline "drone" on the GX, which we experienced on it and the 4Runner when they first came out. This repair involves installing a vibration damper on the front differential and replacing an intermediate shaft and slip yoke at the steering column. The folks at Toyota communications say there haven't been enough complaints recorded on the Toyota side to warrant a TSB. Speak with the Toyota zone service manager who handles the dealership where you bought the vehicle. Be nice, have a friendly approach, and explain the situation. See if he can perform the Lexus TSBs on your Toyota in an attempt to correct your problems. Perhaps you can work something out.

How To Reach AlexIf you have a technical question regarding your pickup, SUV, or van, feel free to contact Alex, a master technician with the National Institute for Automotive Service Excellence. Send a letter to him in care of Truck Trend Garage, 831 S. Douglas Street, El Segundo, CA 90245, or e-mail us at trucktrend@sourceinterlink.com. Please include the VIN with your question. Due to the volume of questions received every month, we cannot guarantee that everyone's question will be personally answered or will appear in the magazine.

Can't wait for help with a problem you're having with your Truck or SUV? Ask the expert we trust here at Truck Trend Garage--visit Alex Steele at www.RealWorldAutomotive.com.